Sub-barrier fusion of two-neutron halo nuclei

The tunneling of composite systems, where breakup may occur during the barrier penetration process, is considered in connection with the fusion of halo-like radioactive, neutron- and proton-rich nuclei, on heavy targets. The large amount of recent and new data clearly indicates that breakup hinders the fusion at energies near and below the Coulomb barrier. However, clear evidence for enhancement due to halo properties seems to over ride the breakup hindrance at lower energies, owing, to a large extent, to the extended matter density distribution. In particular we report here that at sub-barrier energies the fusion cross section of the Borromean two-neutron halo nucleus (6)He with the actinide nucleus (238)U is significantly enhanced as compared to the fusion of a similar projectile with no halo. This conclusion differs from that of the original work, where it was claimed that no such enhancement ensues. This sub-barrier fusion enhancement is also observed in the (6)He + (209)Bi system. (C) 2010 Elsevier B.V. All rights reserved.

FAPERJ

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)

CNPq

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

FAPESP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PRONEX

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Instituto Nacional de Ciencia e Tecnologia de Informacao Quantica-MCT (INCT)

Ministério da Ciência, Tecnologia e Inovação do Brasil (MCTI)